The earnings season had a flying start with equity markets scaling record highs, owing to a slew of upbeat economic data, strong corporate performance and President Donald Trump's tax reform proposal. However, the performance has been a mixed bag for utilities, with some beating market expectations, while a few failing to do so.We will now discuss the performance of three companies, Dominion Energy Inc, NextEra Energy Inc and Duke Energy Corp (read: Utility ETFs to Safeguard Your Portfolio).Dominion Energy IncShares of Dominion Energy Inc D gained 0.7% at market close on Oct 30, 2017, owing to better-than-expected earnings. The company reported a year-over-year increase of 1.5% in net quarterly revenues.Q3 PerformanceDominion reported non-GAAP earnings per share of $1.04, which surpassed the Zacks Consensus Estimate of $1.03 but came in lower than the year-ago figure of $1.14. However, revenues of $3.179 billion failed to beat the consensus mark of $3.327 billion. Income from operations increased to $1.2 billion from $1.145 billion in the year ago quarter.Operating EarningsPower Delivery reported operating earnings of $138 million, decreasing from $139 million a year ago.Power Generation registered operating earnings of $369 million, decreasing from $650 million a year ago.Gas Infrastructure reported operating earnings of $187 million, increasing from $135 million a year ago.Corporate and other incurred operating loss of $22 million compared with a loss of $208 million a year ago.OutlookDominion Energy expects full-year 2017 operating earnings to be in the range of $3.40-$3.90 per share and fourth quarter operating earnings in the band of $0.80-$1.00 per share.NextEra EnergyShares of NextEra Energy Inc. NEE lost 0.3% at market close on Oct 26, 2017, owing to the revenue miss. The company reported a 0.06% year-over-year increase in net quarterly revenues. Moreover, it beat the Zacks Consensus Estimate on earnings but missed on revenues.Q3 PerformanceNextEra Energy reported non-GAAP earnings per share (EPS) of $1.85, increasing 6.3% year over year and beating the Zacks Consensus Estimate of $1.75. However, revenues of $4.808 billion missed the consensus mark of $4.893 billion.The company reported operating income of $1.399 billion, reflecting an increase from $1.279 billion a year ago.Revenue PerformanceFlorida Power and Light revenues increased to $3.477 billion from $3.283 billion a year ago.NextEra Energy Resources revenues declined to $1.333 billion from $1.430 billion a year ago.GuidanceNextEra Energy reiterated its adjusted EPS guidance range of $6.35-$6.85 for 2017 and $6.80-$7.30 for 2018.Duke Energy CorpShares of Duke Energy Corp DUK gained 0.30% at market close on Nov 3, 2017, after it surpassed the earnings estimates for the third quarter of 2017. The company reported a year-over-year decrease of 5% in net quarterly revenues.Quarterly PerformanceDuke Energy reported non-GAAP earnings per share of $1.59, which surpassed the Zacks Consensus Estimate of $1.56 but fell short of the year-ago earnings of $1.68. However, revenues of $6.482 billion failed to beat the consensus mark of $6.746 billion. Operating income declined to $1.695 billion from $1.954 billion a year ago.Segment PerformanceElectric Utilities and Infrastructure reported operating revenues of $6.129 billion, decreasing from $6.340 billion a year ago. Segment income amounted to $1.020 billion, down from $1.189 billion a year ago.Gas Utilities and Infrastructure reported operating revenues of $272 million, increasing from $89 million a year ago. Moreover, segment income amounted to $19 million, up from $15 million a year ago.Commercial Renewables reported operating revenues of $95 million, decreasing from $139 million a year ago. Segment loss amounted to $49 million, up from $24 million a year ago.Other Revenues amounted to $35 million, increasing from $32 million a year ago. Segment expenses totaled $34 million, down from net expense of $181 million a year ago.OutlookDuke Energy narrowed its full-year 2017 adjusted earnings guidance to $4.50-$4.60 per share, from its prior guidance range of $4.50-$4.70 per share.In the current scenario, we believe it is prudent to discuss the following ETFs that have a relatively high exposure to the three companies.Utilities Select Sector SPDR Fund XLUXLU is one of the most popular funds in the utility space. It primarily provides exposure to the U.S. companies involved in electricity or natural gas. The fund has AUM of $7.7 billion and is a relatively cheaper bet as it charges a fee of 14 basis points a year. It has a 10.2% allocation to NextEra Energy, 8.2% to Duke Energy and 7.4% to Dominion Energy (as of Nov 3, 2017). The fund has returned 15.1% in a year and 13.7% year to date (as of Nov 3, 2017). It has a Zacks ETF Rank #3 (Hold) with a Medium risk outlook.Vanguard Utilities ETF VPUThis ETF offers targeted exposure to U.S. utility companies. It has AUM of $2.7 billion and charges a fee of 10 basis points a year. It has an 8.5% allocation to NextEra Energy, 7.2% to Duke Energy and 6.0% to Dominion Energy (as of Sep 30, 2017). The fund has returned 16.2% in a year and 13.5% year to date (as of Nov 3, 2017). It has a Zacks ETF Rank #3 with a Medium risk outlook.iShares U.S. Utilities ETF IDUThis ETF offers targeted exposure to U.S. utility companies. It has AUM of $746.9 million and charges a fee of 44 basis points a year. It has an 8.6% allocation to NextEra Energy, 7.6% to Duke Energy and 6.4% to Dominion Energy (as of Nov 2, 2017). The fund has returned 15.6% in the last one year and 13.5% year to date (as of Nov 3, 2017). It has a Zacks ETF Rank #3 with a Medium risk outlook.Want key ETF info delivered straight to your inbox?Zacks’ free Fund Newsletter will brief you on top news and analysis, as well as top-performing ETFs, each week. Get it free >> Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report NextEra Energy, Inc. (NEE): Free Stock Analysis Report Duke Energy Corporation (DUK): Free Stock Analysis Report Dominion Energy Inc. (D): Free Stock Analysis Report VIPERS-UTIL (VPU): ETF Research Reports SPDR-UTIL SELS (XLU): ETF Research Reports ISHARS-US UTIL (IDU): ETF Research Reports To read this article on Zacks.com click here. Zacks Investment Research Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report